Another Fuel Pressure Question

88vetteZ52 · 10-21-2002, 12:46 AM

I have an 88 auto coupe.

I am running 8psi of boost. 1.6 roller rockers. stock TB wtih airfoil. hooker long tube headers. Gutted cats. Holley adjustable fuel pressure regulator.

I am wondering what suggested fuel pressure I should be running. Right now, with the vac removed, it is at 47psi. It seems to do ok, but I am wondering if there is an optimal setting?

[Modified by 88vetteZ52, 3:53 AM 10/21/2002]

SPD DMN · 10-21-2002, 03:55 PM

There is no magical number and will vary depending on climate and altitude. 43-48 is a normal operating range though.

Mo_Bandy · 11-08-2002, 04:24 AM

88 Vette,

Your pressure will determine how rich your Air fuel mixture will be at WOT... I'm running stock 24's at the moment, running 8 pounds into a intercooler.

I'm shooting right at 12.5 or right at .900 to .920 monitoring the O2's

I am right at about 75 pounds of fuel pressure WOT and 41 at idle (LT-1) ... if you can give me your approximate horsepower and what injectors your running, I can give you more specific answers...

If you are running close to 480 (where I am) your need to be close to about 36 pounds of fuel... obviously the larger the injector the less pressure but at idle too large of injectors can be tough to dial in...

Summerizing.. you sound good from idle through probably 4000 , but you need the extrra fuel pressure t keep from detonating at redline as it will lean out rapidly. I have personally seen 11 degrees of spark knock at 5600 as the air fuel was at 13.2... you should be minimum 12.5 - 12 at WOT

email me if you like...

mo